Eeik adolf edgren



(No Model.) Y

E. A. EDGREN.

KEYBOARD FOR MUSICAL INSTRUMENTS.

No. 520,982. Patented June 5, 1894.

WITNESSES:

INVENTIOR j/zi v M 7M ATTO R N EY UNITED STATES ERIK ADOLF EDGREN,

PATENT OFFICE.

OF NEW YORK, N. Y.

KEYBOARD FOR MUSICAL INSTRUMENTS.

SPECIFICATION forming part of Letters Patent No. 520,982, dated June 5,1894.

Application filed February 6, 1893.

To aZZ whom it may concern.-

Be it known that I, ERIK ADOLF EDGREN, a subject of the King of Swedenand Norway, and a resident of New York city, in the county and State ofNew York, have invented certain new and useful Improvements in Keyboardsfor Pianos, Organs, and other Like Musical Instruments, of which thefollowing is a specification.

My invention consists in the improved construction and arrangement of anauxiliary key board of a piano, organ or other like musical instrument,whereby it may be readily adjusted laterally either way from the truenormal position, to other positions so that while the key board willapparently be in the normal key the music will be given in a higher orlower key to suit the voice of the performer not in harmony with thenormal key of the instrument, the improvement being adapted forapplication to instruments in use, all as hereinafter fully describedreference being made to the accompanying drawings, in which- Figure 1,is a plan view of part of an upright piano with the key board of myinvention as applied to a piano of ordinary construction. Fig. 2, is atransverse section on line to w, of Fig. 1.

In addition to the ordinary key board I employ an auxiliary key boarda'bc, connected so as to slide laterally, that is, lengthwise of the keyboard a suitable distance each way from the normal position, as in thisexample, the front edge a of the keyboard rests on the upper surface ofthe front part d of the frame and the rear edge e, of the said key boardis hung by the sliding metallic brackets e, on the slide way rods f,mounted on a bar to, applied to hold the key board and secured by slidebolts 2, thus supporting the key board so that it may be shifted freely,and also so that the front edge maybe raised slightly to facilitate theshifting which is favored thereby.

For application to keys h and 1." of the ordinary arrangements ininstruments already in use, I provide auxiliary keys 71. and i pivotedto the back edge e of the sliding key board so as to range over theordinary keys h and iand transmit the motion to them using intermediatetransmitting keys 1%, over Serial No. 461,291. (No model.)

the keys 72. which are lower than keys i and cannot therefore be actedon directly by the auxiliary keys, said transmitting keys being soconnected to the bar 11, on which the key board slides and by which itis secured in the instrument that they remain in constant relation withthe keys h and vibrate freely with the other keys. In this example theyare represented as connected by thin flexible strips 0 of metal, andkeys 7L2 and i are also suitably connected to edge piece 0 of the keyboard by like strips 19, but they may of course be connected in anyother suitable way. The keys 7?.2 are in this case provided with a guidespur g at the front extremity working in a vertical guide slot in theinner edge of the front piece a of the auxiliary key board to guide thekeys against lateral play, but this may be omitted if preferred.

A scale s is provided on the adjustable key board to gage the shiftingas by the mark t, and a toothed rack as a, on the key board, and apinion e on the fixed bar w, may be used for shifting the key board, thepinion having a stud as m by which to apply the ordinary tuning key forturning it.

A notched spring pawl as 00' may be used in connection with the teeth ofthe pinion for locking the key board in position or any other approvedmeans may be employed, for instance, the toothed bar a, may be movableagainst the pinion and a spring 4y may be employed to press it againstthe pinion and produce friction on the journals of the pinion.

Ielaim- The combination with the ordinary key board of a piano, organ orlike instrument, of the auxiliary key board a-b-c, the attaching bar w,detachably secured to the instrument and having the said auxiliary keyboard hinged to it, the auxiliary keys k and a? pivoted to the back edge0 of the said auxiliary key board, and the transmitting keys m, securedto the bar to, all constructed and ar= ranged substantially asdescribed.

Signed at New York city, in the county and State of New York, this 6thday of December,

ERIK AD OLF ED GREN. Witnesses:

W. J. MORGAN, C. E. WHITNEY.

